OUTCOME OF TREATMENT FOR BILATERAL CONGENITAL CATARACTS* BY Richard M. Robb, MD AND (BY INVITATION) Robert A. Petersen, MD INTRODUCTION
THE
VISUAL RESULTS OF CATARACT SURGERY IN CHILDREN HAVE GENER-
ally been poorer than in adults.1-3 The difference is due in part to the various types of amblyopia that develop in children with cataracts, the association of nystagmus with cataracts of early onset, and the presence of other ocular abnormalities that adversely affect vision in eyes with developmental lens opacities. Following reintroduction of the aspiration technique for cataract removal by Scheie in 1960,4 the surgical procedures for removal of the lens in childhood have been improved56 and earlier surgery for congenital cataracts has been encouraged. 7-9 A current assessment of the outcome of surgery for congenital cataracts therefore seemed to be in order, and this paper addresses our experience with a group of children with bilateral congenital cataracts of diverse etiology. PATIENTS AND METHODS
Fifty-one patients with bilateral congenital cataracts who had surgery by the authors at Boston Children's Hospital between 1971 and 1990 and whose postoperative visual acuity could be determined by recognition acuity tests were studied retrospectively. The cataracts were considered congenital if they were identified within the first 6 months (24 patients), were dominantly inherited in families with a history of congenital cataracts (19 patients); or were lamellar in configuration, suggesting an early developmental origin (19 patients). These categories were not mutually exclusive. At the time of cataract surgery, patient age ranged from 1 month to 22 years, depending on the time of presentation, the size and density of the cataracts, and the visual function of the patient as determined by visual behavior or measurement of visual acuity. Removal of *From The Department of Ophthalmology, Boston.
TR. AM. OPHTH. Soc. vol. LXXXX, 1992
Children's Hospital and Harvard Medical School,
184
Robb & Petersen
lens material was accomplished by aspiration after incision of the anterior lens capsule or by a combination of aspiration and suction-cutting. In the earlier cases of the series, the posterior capsule was left intact at the time of aspiration and was later incised with a discission knife if it opacified. In more recent cases the posterior capsule was often removed with the suction-cutting instrument at the time of initial surgery. In a few patients an opacified posterior capsule was opened with a neodymium-yttrium aluminum garnet (Nd:YAG) laser. In most eyes, either a peripheral or a full iridectomy was performed as part of the initial surgery, the choice depending on how well the pupil dilated preoperatively. Aphakic correction was accomplished with spectacles or contact lenses. The patients were followed until 3 to 30 years of age (mean, 10.3 years; median, 8.5 years) for measurement of final visual acuity. Records were reviewed to identify patients with nystagmus, strabismus, amblyopia, and glaucoma. Nystagmus was recognized by clinical inspection, and strabismus was defined as overt ocular misalignment on cover test. Strabismic or deprivational amblyopia was considered to be present when that diagnosis was made by the examining physician. Since patching of the dominant eye was frequently carried out, the final visual acuities do not necessarily reflect the presence of amblyopia at some earlier point in time. Glaucoma was considered to be present when the ocular pressure was over 22 mm mercury on repeated measurements. The condition of the anterior-chamber angle was assessed by Koeppe gonioscopy. RESULTS
Patients with congenital lamellar opacities had the best visual outcome from cataract surgery, and surgery improved their vision even if it was performed as late as the second decade (Table I). The average postoperative visual acuity in the better eye of 19 patients with lamellar cataracts was 20/38, and it improved to 20/30 if three patients who had nystagmus were excluded. Surgery for lamellar cataracts was performed from 7 months of age to 20 years, the average age at operation being 9.7 years. Deprivational amblyopia did not appear to occur, even in the older patients with bilateral lamellar or other partial cataracts unless the lens opacities were asymmetrical in the two eyes. The visual acuity in the better eye of all patients whose surgery was performed after 3 years of age improved to 20/40 or better, except in the previously mentioned patients with nystagmus and high myopia (Fig 1). The visual outcome was less good in patients with more extensive cataracts (Table I), whose surgery was usually performed in the first year
Bilateral Congenital Cataracts 20 25
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32
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50 4 63
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185
80
F 100
THE
VISUAL RESULTS OF CATARACT SURGERY IN CHILDREN HAVE GENER-
ally been poorer than in adults.1-3 The difference is due in part to the various types of amblyopia that develop in children with cataracts, the association of nystagmus with cataracts of early onset, and the presence of other ocular abnormalities that adversely affect vision in eyes with developmental lens opacities. Following reintroduction of the aspiration technique for cataract removal by Scheie in 1960,4 the surgical procedures for removal of the lens in childhood have been improved56 and earlier surgery for congenital cataracts has been encouraged. 7-9 A current assessment of the outcome of surgery for congenital cataracts therefore seemed to be in order, and this paper addresses our experience with a group of children with bilateral congenital cataracts of diverse etiology. PATIENTS AND METHODS
Fifty-one patients with bilateral congenital cataracts who had surgery by the authors at Boston Children's Hospital between 1971 and 1990 and whose postoperative visual acuity could be determined by recognition acuity tests were studied retrospectively. The cataracts were considered congenital if they were identified within the first 6 months (24 patients), were dominantly inherited in families with a history of congenital cataracts (19 patients); or were lamellar in configuration, suggesting an early developmental origin (19 patients). These categories were not mutually exclusive. At the time of cataract surgery, patient age ranged from 1 month to 22 years, depending on the time of presentation, the size and density of the cataracts, and the visual function of the patient as determined by visual behavior or measurement of visual acuity. Removal of *From The Department of Ophthalmology, Boston.
TR. AM. OPHTH. Soc. vol. LXXXX, 1992
Children's Hospital and Harvard Medical School,
184
Robb & Petersen
lens material was accomplished by aspiration after incision of the anterior lens capsule or by a combination of aspiration and suction-cutting. In the earlier cases of the series, the posterior capsule was left intact at the time of aspiration and was later incised with a discission knife if it opacified. In more recent cases the posterior capsule was often removed with the suction-cutting instrument at the time of initial surgery. In a few patients an opacified posterior capsule was opened with a neodymium-yttrium aluminum garnet (Nd:YAG) laser. In most eyes, either a peripheral or a full iridectomy was performed as part of the initial surgery, the choice depending on how well the pupil dilated preoperatively. Aphakic correction was accomplished with spectacles or contact lenses. The patients were followed until 3 to 30 years of age (mean, 10.3 years; median, 8.5 years) for measurement of final visual acuity. Records were reviewed to identify patients with nystagmus, strabismus, amblyopia, and glaucoma. Nystagmus was recognized by clinical inspection, and strabismus was defined as overt ocular misalignment on cover test. Strabismic or deprivational amblyopia was considered to be present when that diagnosis was made by the examining physician. Since patching of the dominant eye was frequently carried out, the final visual acuities do not necessarily reflect the presence of amblyopia at some earlier point in time. Glaucoma was considered to be present when the ocular pressure was over 22 mm mercury on repeated measurements. The condition of the anterior-chamber angle was assessed by Koeppe gonioscopy. RESULTS
Patients with congenital lamellar opacities had the best visual outcome from cataract surgery, and surgery improved their vision even if it was performed as late as the second decade (Table I). The average postoperative visual acuity in the better eye of 19 patients with lamellar cataracts was 20/38, and it improved to 20/30 if three patients who had nystagmus were excluded. Surgery for lamellar cataracts was performed from 7 months of age to 20 years, the average age at operation being 9.7 years. Deprivational amblyopia did not appear to occur, even in the older patients with bilateral lamellar or other partial cataracts unless the lens opacities were asymmetrical in the two eyes. The visual acuity in the better eye of all patients whose surgery was performed after 3 years of age improved to 20/40 or better, except in the previously mentioned patients with nystagmus and high myopia (Fig 1). The visual outcome was less good in patients with more extensive cataracts (Table I), whose surgery was usually performed in the first year
Bilateral Congenital Cataracts 20 25
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32
-
50 4 63
-
>-
185
80
F 100
